It looks like an item I listed is going to sell for more than I expected (lucky me). I listed the item as RM second class delivery and would have got proof of postage, but I think it would be better now to have it signed for. This is after some horror stories I've heard on forums about buyers saying goods haven't arrived. I obviously wouldn't charge the buyer the additional cost, but would it be appropriate to ask the buyer if I could send it signed for instead?